The present invention relates to a punched card control system for an embroidery machine, the system operating to control a drive mechanism in the machine which controls the movement of an embroidery creel.
A device for stitching, quilting or embroidering lengths of cloth or the like is known in which a conventional embroidery creel includes two carriages. The carriages are movable in mutually perpendicular directions so that the embroidery operation can be carried out by the machine in which the device is used. Control of the carriage movements is effected by way of a computer in which instructions are provided on a jacquard tape or card. The jacquard tape is punched in several rows according to a specific code which corresponds to the desired thread pattern. As the tape is being read, it moves directly against a number of pins each of which triggers a pulse when it senses a hole in the tape. However, when the tape is read in this manner, considerable interference due to, e.g., physical damage or taped over holes, may occur due to false actuations by the pins.
In addition, a drive arrangement for adjustment of embroidery frames in embroidery machines is known in which adjusting movement of the embroidery frames is provided in mutually perpendicular directions by means of conventional hydraulic adjustment drive mechanisms. These hydraulic drive mechanisms are connected with actual value transducers, and are controlled with electro-hydraulic control valves by a desired value transducer which is controlled by punched cards. Thus, a control device is provided which represents a considerable reduction in size of the known automatic mechanical control for embroidery machines, wherein movements representing a direction of rotation and rotational speeds in either direction are generated in the usual manner in a mechanism which is considerably reduced in size, and these movements are transferred to the desired value electrical transducer. Of course, such an arrangement can only be applied in new embroidery machines, since most all parts in existing automatic control mechanisms in embroidery machines would not be required. This arrangement is also very expensive, since it must effect an adjustment of the desired value transducer by mechanical means.
In the known arrangement discussed above, it is also suggested that the electrical contacts be controlled directly by a punched card which, for example, could be implemented by means of light sensitive electrical sensors. It is also known to transfer a punched card directly through a electrical or electronic reader wherein appropriate pulses are then triggered. These punched card arrangements have a proven disadvantage, however, in that the punched cards which are used must be new, i.e., they must not be physically damaged, nor may they have oil spots or the like such as might tend to make the cards translucent and falsely trigger the sensors in the reader.
Changes in the hole patterns in punched cards used in the embroidery industry occur quite often, and such changes are usually manually effected by a foreman with the aid of punch pliers. During the correction of a punched card, some of the existing holes may be taped over with clear or translucent adhesive tape strips. Also, it has become known that if there are, for example, oil spots on the punched card, which occurs quite often in the embroidery industry, the punched card becomes translucent. Because of the taped over areas, oil spots and the like which provide translucent regions on the cards, the card reader sensors are actuated even though no holes are actually present at such regions.
An object of the present invention is to overcome the above disadvantages and to provide a punched card control system for an embroidery machine which is simple to assemble and, nevertheless, efficient in its operation.
In accordance with the present invention, a punched card control system for an embroidery machine which has an embroidery creel and a first drive mechanism for driving the embroidery creel, includes a number of lifter rods each arranged to sense a corresponding hole in successive groups of holes arranged in a card, each group of holes representing an operating instruction for the embroidery machine. A feed mechanism advances the card past the lifter rods while each rod is in a rest position relative to the feed mechanism, so that the holes of each group are successively confronted by corresponding ends of the lifter rods. The feed mechanism then displaces the card a certain distance toward the rods so that those rods whose ends confront holes in the card remain stationary, while the remaining rods are contacted at their ends by the card which then moves these rods from their rest positions. A reading device including electrical switching elements responds to the condition of each lifter rod and provides corresponding output signals over a number of line channels. A control device coupled between the reading device channels and the first drive mechanism controls the first drive mechanism to adjust the movement of the embroidery creel in accordance with the output signals provided over the channels.
With the punched card control system of the present invention, each punched card is read mechanically with the result that minor damage such as oil spots on the card does not result in a false reading but, while electrical or electronic control of the drive mechanisms in the embroidery machine can take place. Mechanical reading and electrical or electronic reading techniques are combined so as to provide a considerable reduction in the number of mechanical parts used as compared to conventional automatic control systems. Yet, the advantages attendant to mechanical reading of the punched cards are maintained. Since heavy mechanical parts are not attached to the lifter rods, these rods can be of a much lighter construction and the forces required of springs which return them to their rest positions can be made considerably smaller. This arrangement also greatly reduces the wear of the punched cards since the contact pressure exerted by the lifter rods against the cards when the rods are at their rest positions can be greatly reduced or eliminated.
Existing automatic embroidery machines can also be easily converted in accordance with the present invention, since only appropriate electrical or electronic switching elements need be provided for already existing lifter rods which read the punched cards. A drive mechanism for driving the creel must also be provided. It can be shown that a punched card control system according to the present invention allows a large number (about 350) of the mechanical parts usually required in an embroidery machine to be omitted, which represents about 50 to 60% of the total number of mechanical parts normally provided. Accordingly, higher operating speeds and correspondingly faster stitch sequences can be realized, and a significant noise reduction will result as well. This noise reduction can be realized not only in new embroidery machines constructed according to the present invention, but also in old embroidery machines which are modified in accordance with the invention. In addition, wear and tear, the need for repairs, and lubrication and maintenance costs are significantly reduced, while the durability of the machine is substantially increased.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.